I am looking to add parameters to the edit-view of my component's menu editor on the fly instead of statically defining them as you normally would (as described : https://docs.joomla.org/J3.x:Developing_a_MVC_Component/Adding_a_variable_request_in_the_menu_type ).

I have created a plugin and implemented onContentPrepareForm. Within the plugin I construct xml for fields with the name "params" so that this data will be stored in the [params] column for the menu.

The parameters are shown just fine on the form, however the data is not saved. I have traced this through the bowels of the JForm joomla code and it turns out the JForm framework is discarding all of the custom fields that have been added dynamically.

* Specifically (and this is where I need help) * JModelForm::validate() calls JForm::validate() calls JForm::findFieldsByGroup(). This last call eliminates my custom fields. If I comment out the first call to validate(), the data for my custom fields is stored.

Here's a sample of my plugin showing how I add the XML on the fly.

public function onContentPrepareForm( $form, $data)
$option = JFactory::getApplication()->input->get('option');
$view = JFactory::getApplication()->input->get('view');

$modifyForm = false;

// check if this is a menu item for my component
if($option == 'com_menus' && $view == 'item' && array_key_exists('component_id', $data))
$myComponent = JComponentHelper::getComponent('com_mycomponent');
if($data['component_id'] == $myComponent->id)
$modifyForm = true;

            $testXml = '<fields name="params">
                            <fieldset name="basic" label="FIELDSET-LABEL">
                                <field name="test-field" type="list" label="test-field-label" description="test-field-description">
                                <option value="">Default</option>
                                <option value="0">Zero</option>
                                <option value="1">One</option>
            $xmlElement = new SimpleXMLElement($testXml);

1 Answer 1


Just wanted to note that the same question was asked by @ajhuddy in Joomla! General Development maillist and it has an answer.

**** SOLVED ****

(Thanks Hannes for leading me to the answer)

It seems to be key in the onContentPrepareForm part of the plugin to only make a change to the form if $form->getName() evaluates to the form you are wanting to alter.

  • Yes that was me I should have updated this question Commented Feb 27, 2015 at 14:55

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